Sponson tow plate-mounted helicopter armament apparatus and associated methods

ABSTRACT

External armament apparatus, including a machine gun, an associated ammunition box for supplying belted ammunition to the gun, a flare dispenser, a missile launcher or other external stores apparatus, and a forward looking infrared sensor (FLIR), is exteriorly supported on a landing gear sponson tow plate of a helicopter, adjacent a cabin area gunner&#39;s window. The external mounting of the gun and other armament apparatus frees up cabin space, permits the gunner&#39;s window to be closed with the gun in a ready position, and permits a 0.50 caliber machine gun to be used an alternative to either a 7.62 mm mini-gun or a single barrel 7.62 mm machine gun adjacent the gunner&#39;s window.

BACKGROUND OF THE INVENTION

[0001] The present invention generally relates to aircraft armamentapparatus and, in a preferred embodiment thereof, more particularlyrelates to the external mounting of armament apparatus on a helicopter.

[0002] The “Blackhawk” military helicopter has a cabin area positionedbehind the cockpit area and having sliding gunner's windows on oppositesides thereof. Using conventional mounting techniques, either 7.62 mmmini-guns or single barrel 7.62 mm machine guns may be mounted on thehorizontal sill areas of these gunner's windows on articulated supportlinkage assemblies that permit the guns to be swung outwardly throughthe opened windows to use orientations, or inwardly through the openedwindows to storage orientations. Various well-known problems,limitations and disadvantages are associated with this conventionalhelicopter armament mounting technique.

[0003] For example, with both the 7.62 mm mini-guns and the singlebarrel 7.62 mm machine gun, the articulated, sill-mounted supportstructure for the gun has an undesirable amount of positional “play”therein which, although necessary for gun adjustment and deployment,substantially degrades the firing accuracy of the gun. Additionally,while the single barrel 7.62 mm machine gun has an ammo box mounteddirectly on the gun, the 7.62 mm mini-gun has an external ammo box thatmust be positioned in the adjacent cabin area, with the beltedammunition fed from the ammo box, out the gunner's window and to thegun. This, of course, undesirably clutters up the cabin area. Anotherproblem associated with this sill mounting of both the 7.62 mm mini-gunand the 7.62 mm single barrel machine gun is that the gunner's windowscannot be closed with the guns in their ready positions. This inabilityto close these windows leads to uncomfortably cold cabin temperaturesduring cold weather missions, and fuel mist potentially entering thecabin area during in-flight refueling.

[0004] With either the 7.62 mm mini-gun or the 7.62 mm single barrelmachine conventionally mounted on a cabin area gunner's window sill, themaximum upward firing angle of the gun relative to horizontal isapproximately 1.5 degrees. This is due to the fact that, with thesill-mounted gun pointed forwardly along a side of the helicopter, thisis the maximum upward firing elevation angle of the gun that (with apredetermined margin of safety) will position its bullet path safelybeneath the helicopter's forwardly drooped rotor blade tip path topreclude bullet impact with the spinning rotor blades. This 1.5 degreemaximum upward elevational firing angle of the gun undesirably limitsthe maximum firing range of the gun when the gun is swung away from itsforwardly pointed orientation—for example when it is being fired off tothe side of the helicopter or to the rear thereof.

[0005] Yet another limitation presented by this conventional helicopterwindow sill-mounting of machine guns is that larger machine guns, suchas to 0.50 caliber machine guns, are difficult to deploy, and, becauseof their weight, intensify crash load issues.

[0006] These problems, limitations and disadvantages associated withconventional gunner's window sill mounting of machine guns wereaddressed by the present applicant's helicopter sponson towplate-mounted armament apparatus illustrated in his U.S. Pat. No.6,250,197, the disclosure of which is hereby incorporated by referenceherein in its entirety. In such armament apparatus, a machine gun, ammobox and flare dispenser are externally mounted, adjacent a gunner'swindow, on a specially designed landing gear sponson replacement towplate. The external machine gun mounting permitted by this speciallydesigned system frees up cabin space, permit's the gunner's window to beclosed with the gun in a ready position, and permits a 0.50 calibermachine gun to be used as an alternative to either a 7.62 mm mini-gun ora single barrel 7.62 mm machine gun adjacent the gunner' window.

[0007] While the tow plate-mounted helicopter armament apparatusillustrated and described in U.S. Pat. No. 6,250,197 provides theadvantages set forth above, it has been found in the development of thesystem that it would be desirable to provide it with variousmodifications and improvements to the design—such as improvedpositioning of its components, the provision of additional externalarmament, cost reduction, enhanced positional control of the machinegun, and maintenance and installation simplification—would be desirable.It is to these improvements in the design of the sponson towplate-mounted external helicopter armament apparatus illustrated anddescribed in U.S. Pat. No. 6,250,197 that the present invention isprimarily directed.

SUMMARY OF THE INVENTION

[0008] In carrying out principles of the present invention, inaccordance with a preferred embodiment thereof, specially designedexternal armament apparatus is secured to an aircraft landing gearstructure, representatively a landing gear sponson tow plate of ahelicopter. Although various components of the armament apparatus may bedeleted, and various component combinations may be utilized depending onthe helicopter's mission, in a representatively complete form thereofthe external armament apparatus illustratively comprises:

[0009] 1. A pintle arm assembly secured to and projecting upwardly froma central outboard side portion of the tow plate;

[0010] 2. A yoke assembly secured to an upper end portion of the pintlearm assembly for horizontal pivoting relative thereto;

[0011] 3. A cradle assembly secured to the yoke assembly for horizontalpivoting therewith and vertical pivoting relative thereto;

[0012] 4. A machine gun, representatively a .50 caliber machine gun,operatively carried by the cradle assembly;

[0013] 5. An ammunition box/booster assembly mounted on a top side edgeportion of the tow plate, inboard of the pintle arm assembly, andadapted to hold a length of belted ammunition feedable to the machinegun;

[0014] 6. A flare dispenser mounted on a rear end portion of the towplate and positioned generally beneath the pivot area of the machinegun;

[0015] 7. An external stores assembly including a support structuresecured to the outboard side of a lower end portion of the pintle armassembly and external stores apparatus, representatively a missilelauncher, operatively mounted on the support structure; and

[0016] 8. A forward-looking infrared (FLIR) sensor secured to a frontend portion of the tow plate.

[0017] The machine gun, which may be of various types, including, forexample, a .50 caliber gun, a 7.62 mm mini-gun, or a single barrel 7.62mm machine gun, is operatively supported outside a gunner's window tothereby permit the window to be closed when the gun is not being used,and the external positioning of the ammunition box reduces clutter inthe cabin area of the helicopter. The positioning of the flare dispenserbeneath the pivot area of the machine gun prevents potentialinterference between the flare dispenser and the gun barrel/projectilepath when the gun is being pivoted in a depressed elevationalorientation.

[0018] In one illustrative embodiment thereof, the pintle arm assemblyincludes a pintle block member secured to a central outboard sideportion of the tow plate and has an opening extending therethrough alongan upwardly and rearwardly inclined axis. An elongated, substantiallystraight support arm member extends along a longitudinal axis and has alower end portion coaxially locked within the pintle block opening by atransverse retaining pin structure. The lower end of the support arm hasa conically tapered annular outer side surface portion which engages asimilarly tapered interior surface portion of the pintle block opening.A tapered annular collet member is forced against a second conicallytapered annular interior surface area of the pintle block opening by anut tightened onto a threaded lower end of the support arm.

[0019] In an alternate embodiment of the pintle arm assembly, thesupport arm has a uniform cross-section along its length and iscaptively retained within the pintle block opening by a pair ofexpansion pins extending transversely through the pintle block and thelower end of the support arm.

[0020] The machine gun, and its associated cradle and yoke assemblies,are mounted on the rearwardly and upwardly offset upper end of theinstalled support arm for azimuth and elevation rotation relative to thepintle arm assembly respectively about vertical and horizontal axes, thevertical axis representatively being forwardly and upwardly inclinedrelative to a vertical reference axis at a small angle which ispreferably about three degrees to match the rotor system forward tilt.

[0021] According to another feature of the invention, a speciallydesigned elevation limiting system may be associated with the machinegun, when the external stores assembly is included in the overallexternal armament apparatus, and serves to prevent the gun's bullet pathfrom intersecting a front portion of the installed missile launcherassembly when the gun is in a forward portion of its azimuth arc. Theelevation limiting system functions, in response to horizontal azimuthrotation of the gun, to automatically provide a downward gun rotationlimit angle which, with the gun in a predetermined forward portion ofits azimuth arc, is less than the downward gun rotation limit angle whenthe gun is in a predetermined rearward portion of its azimuth arc.

[0022] In a preferred embodiment thereof, the elevation limiting systemincludes a cam follower/stop member carried for variable driven rotationparallel to the gun's vertical azimuth rotation axis and functioning tovariably block downward rotation of the gun cradle portion in forwardand rearward gun azimuth travel arcs.

[0023] In accordance with another aspect of the invention, a portion ofthe machine gun is removably secured to the cradle structure using anannular trunnion nut member secured to the gun and positioned betweentwo support block portions of the cradle. A diametrically opposite pairof radial openings extending through the trunnion nut are aligned withhorizontal openings extending through the support blocks. To releasablylock the trunnion nut to the support blocks, a pair of speciallyconfigured is nonthreaded locking studs are provided and are insertedinwardly through the support block openings so that nonthreaded innerend portions of the studs are received in the opposed trunnion nutopenings. The inserted studs are releasably locked in place within thehorizontal support block openings by suitable retaining pins extendingdownwardly through upper end openings in the support blocks and havinglower end portions received in transverse openings in the insertedstuds.

[0024] According to another feature of the invention, the externalstores assembly includes an external stores support structure anchoredto the pintle support block and projecting in an outboard direction fromthe tow plate, and provided with adjustment structure permitting theexternal stores apparatus which it carries to be pivotally adjustedabout at least one axis relative to the support structure.Representatively, this adjustment structure provides for elevationaladjustment of the external stores apparatus and includes front and rearelevation adjustment bolts that bear against, and may be variablyadjusted relative to, portions of the supported external storesapparatus. As used herein, the term “external stores” encompassesarmament apparatus, such as missiles, rockets and rocket launchers,additional guns, electronics, etc. which are carried externally to theaircraft and are typically, though not necessarily, jettisonable.

[0025] In accordance with another aspect of the invention, theforward-looking infrared sensor is secured to a front end portion of thetow plate in a manner positioning the sensor in a forwardly spaced apartrelationship with the tow plate. This positioning is representativelyachieved using a mounting structure including a rear block portionsecured to a front edge portion of the tow plate, an elongated mountingmember longitudinally projecting forwardly from the rear block portionand having a front end, and a front block portion secured to the frontmounting member end and overlying and being secured to a top end portionof the sensor.

[0026] The feed booster portion of the ammunition box/booster assemblyincludes a booster housing having disposed therein a sprocketed electricdrive motor operable to engage an ammunition belt disposed in theammunition box and drive it outwardly therefrom for delivery to themachine gun during firing thereof. According to yet another aspect ofthe invention, the drive motor is mounted in a removable booster housingportion of the ammunition box/booster assembly in a unique mannerpermitting the motor to be operatively installed in and removed from thebooster housing without the use of tools of any sort.

[0027] Representatively, the motor is provided with opposite mountingend portions through which locking openings extend. The motor isinserted into the booster housing, through an access opening therein, ina manner positioning the motor end locking openings between facingexterior and interior mounting opening sets formed in the boosterhousing. Removable pin members are inserted through the aligned housingmotor openings to captively retain and operatively position the motorwithin the booster housing. By simply removing the booster housing fromthe ammunition box and removing these pins, the motor can be removedfrom the booster housing without the use of tools, and a replacementmotor can be positioned in the removed booster housing similarly withoutthe use of tools.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1 is a right side elevational view of a front portion of arepresentative helicopter having mounted on a sponson tow plate portionthereof external armament apparatus embodying principles of the presentinvention;

[0029]FIG. 2 is a front outboard top perspective view of the armamentapparatus;

[0030]FIG. 3 is a rear outboard top perspective view of the armamentapparatus;

[0031]FIG. 4 is a rear outboard bottom perspective view of the armamentapparatus;

[0032]FIG. 5 is a front outboard bottom perspective view of the armamentapparatus;

[0033]FIG. 6 is a front outboard top perspective view of the armamentapparatus with an outboard missile portion removed therefrom forillustrative purposes;

[0034]FIG. 7 is a partially exploded perspective view of the armamentapparatus portion shown in FIG. 6, with an ammunition belt removedtherefrom for illustrative purposes;

[0035]FIG. 8 is an enlarged scale, partially exploded perspective viewof a part of the armament apparatus portion shown in FIG. 7, with anammunition box portion removed therefrom for illustrative purposes;

[0036]FIG. 9 is a partially exploded perspective view of the machine gunportion of the armament apparatus;

[0037]FIG. 10 is an enlarged scale partial outer side elevational viewof a trunnion nut portion of the machine gun taken generally along line10-10 of FIG. 9;

[0038]FIG. 11 is a partially exploded perspective view of the armamentapparatus portion shown in FIG. 7, with machine gun and ammunition boxportions removed therefrom;

[0039]FIG. 12 is a partially exploded perspective view of a yoke andcradle assembly portion of the armament apparatus;

[0040]FIG. 13 is a partially exploded perspective view of the armamentapparatus portion shown in FIG. 11, with the yoke and cradle assemblyportion removed therefrom;

[0041]FIG. 14 is an enlarged scale cross-sectional view through a pintlesupport block portion of the armament apparatus taken generally alongline 14-14 of FIG. 13;

[0042]FIG. 15 is a partially exploded perspective view of the armamentapparatus portion shown in FIG. 13, with a support stud portion removedtherefrom;

[0043]FIG. 16 is an assembled perspective view of an alternateembodiment of pintle arm and pintle support block portions of thearmament apparatus;

[0044]FIG. 17 is an exploded perspective view of the pintle support armand support block portions of the armament apparatus shown in FIG. 16;

[0045]FIG. 18 is a partially exploded perspective view of an ammunitionbox/booster assembly portion of the armament apparatus;

[0046]FIG. 19 is an enlarged scale inner side perspective view of thebooster portion of the FIG. 18 ammunition box/booster assembly;

[0047]FIG. 20 is a partially exploded perspective view of the boosterportion shown in FIG. 19;

[0048]FIG. 21 is a perspective view of an external stores supportstructure portion of the armament apparatus;

[0049]FIG. 22 is a partially exploded perspective view of the externalstores support structure of FIG. 21;

[0050]FIG. 23 is a front side elevational view of the missile supportingstructure of FIG. 21;

[0051]FIG. 24 is a front outboard perspective view of the armamentapparatus, with a representative missile launcher portion removedtherefrom, and a forward looking infrared (FLIR) sensor secured to afront edge portion of the sponson tow plate.

[0052]FIGS. 25 and 26, respectively, are simplified top plan and frontelevational views of the helicopter, with the armament apparatus removedtherefrom, diagrammatically illustrating the machine gun elevation andazimuth rotational limits which may be provided in the armamentapparatus with the missile launcher structure removed therefrom;

[0053]FIGS. 27 and 28, respectively, are views similar to those in FIGS.25 and 26 and diagrammatically illustrate the machine elevation andazimuth rotational limits provided, when the missile launcher structureis included in the overall armament apparatus, by a specially designedelevation limiting structure incorporated in the armament apparatus;

[0054]FIG. 29 is an outboard side perspective view of a machine gunmounting portion of the armament apparatus illustrating the operation ofa specially designed gun elevation limiting system embodying principlesof the present invention, a gun support cradle assembly portion of thegun mounting portion being in a forwardly pivoted, depressedorientation;

[0055]FIG. 30 is an enlarged scale detail view of the dashed circle area“A” in FIG. 29;

[0056]FIG. 31 is a rear side perspective view of the machine gunmounting portion shown in FIG. 29, with the cradle assembly being in arearwardly pivoted, depressed orientation; and

[0057]FIG. 32 is an enlarged scale detail view of the dashed circle area“B” in FIG. 31.

DETAILED DESCRIPTION

[0058] Illustrated in FIGS. 1 and 26 is a front portion of a helicopter10, representatively a UH-60 Blackhawk military helicopter, which isparked on the ground 12 and has a horizontally elongated body 14 with afront end 16 and a rear end (not shown) spaced apart along alongitudinal reference axis 18 extending parallel to the ground 12. Thehelicopter body 14 has a left side 20 and a right side 22. At the frontend portion 16 of the body 14 is a cockpit area 24 positioned forwardlyof a cabin area having sliding gunner's windows 26 on its left and rightsides 20,22. A vertically upwardly projecting motor-driven maststructure 28 (see FIG. 26) is disposed rearwardly of the gunner'swindows 26 and is rotatable about a generally vertical mast axis 30 thatis forwardly inclined at a small angle, representatively about threedegrees. In a conventional manner, the mast structure 28 rotationallydrives generally horizontally oriented rotor blades 32 (shown inlongitudinally shortened form in FIG. 26) about the mast axis 30, withthe rotationally driven rotor blades 32 having a blade tip envelope (notshown) with a downwardly depressed front end portion (also not shown).

[0059] Helicopter 10 is rollingly supported on the ground 12 by a rearlanding wheel 36 carried on a strut structure 38 (see FIG. 26) extendingdownwardly and rearwardly from the rear end portion of the body 14, andleft and right forward landing wheels 40. The left and right landingwheels 40 are operatively secured to left and right strut structures 42(see FIG. 1) that extend downwardly and rearwardly from left and rightwheel support sponsons 44 (see FIG. 2) that project outwardly from theleft and right sides of the helicopter body 14 generally below thegunner's windows 26. The right sponson 44 is illustrated in FIG. 2 and,like the left sponson 44, has a metal tow plate 46 suitably bolted, asat 47, to its outboard side 48.

[0060] The tow plates 46 replace the tow plates originally installed onthe sponsons 44, and are larger and stronger that the original towplates, and, as the name implies, are used as attachment points fortowing the helicopter 10 along the ground 12. The tow plates 46 are alsoused for tying the helicopter down. As best illustrated in FIGS. 16 and17 (which show the right tow plate 46), each tow plate 46 has ahorizontally elongated plate-like configuration, and has a front orforward portion 46 a (at which a refueling boom structure 49 may besecured to the sponson 44 as shown, for example, in FIGS. 6 and 7), agenerally circularly shaped rear or aft portion 46 b, a horizontallycentral portion 46 c, and a top edge portion 46 d.

[0061] Referring briefly to FIGS. 1-5 and 24, specially designedexternal armament apparatus 50 is operatively mounted on each of theleft and right sponson tow plates 46. The external armament apparatus 50on each side of the helicopter 10 has the same components (some or allof which may be selectively mounted on their associated tow platedepending on the particular mission of the helicopter), with only theright side external armament apparatus 50 being illustrated herein. Therepresentatively illustrated right side armament apparatus 50 (with itsfull complement of components) includes:

[0062] 1. A pintle arm assembly 52 secured to and projecting upwardlyfrom the outboard side of the tow plate 46;

[0063] 2. A yoke assembly 54 secured to an upper end portion of thepintle arm assembly 52 for horizontal pivoting relative thereto;

[0064] 3. A cradle assembly 56 secured to the yoke assembly 54 forhorizontal pivoting therewith and vertical pivoting relative thereto;

[0065] 4. A machine gun 58 operatively carried by the cradle assembly56;

[0066] 5. An ammunition box/booster assembly 60 mounted on the top sideedge portion 46 d of the tow plate 46, inboard of the pintle armassembly 52, and adapted to hold a length of belted ammunition feedableto the machine gun 58;

[0067] 6. A flare dispenser 62 mounted on the rear end portion 46 b ofthe tow plate 46 and positioned generally beneath the pivot area of themachine gun 58;

[0068] 7. An external stores assembly representatively including amissile launcher assembly 64 (or other external stores apparatus)secured to the outboard side of a lower end portion of the pintle armassembly 52 by an external stores support structure; and

[0069] 8. A forward-looking infrared (FLIR) sensor 66 (see FIG. 24)secured to the front end edge portion 46 a of the tow plate 46.

[0070] Turning now to FIGS. 11 and 13-15, the pintle arm assembly 52includes an elongated, substantially straight tubular support arm member68 which longitudinally extends along a rearwardly and upwardly inclinedaxis 70 (see FIG. 15), and a pintle support block 72. Support arm 68 hasa reduced diameter lower end portion 74 with an externally threadedlower end 76 spaced downwardly apart from a diametrically opposite pairof radially extending circular sidewall locking openings 78 (only one ofwhich is visible in the drawings) in the lower end portion 74.Immediately above the openings 78 the support arm 68 has a conicallytapered annular portion 80 that joins the lower end portion 74 to alarger diameter main longitudinal portion 82 of the support arm 68.

[0071] Welded or otherwise anchored to the upper end of the longitudinalsupport arm portion 82 is a generally vertically oriented tubular socketmember 84 that downwardly and coaxially receives a tubular mounting stud86 having an externally threaded lower end 88, a conically taperedportion 90 disposed above the threaded end 88 and directly below anazimuth stop plate 92. Plate 92 has a circumferentially spaced pair ofazimuth stop projections 94 formed thereon, and an enlarged diametertubular upper end portion 96, having an annular exterior groove 98formed thereon, extends upwardly from the azimuth stop plate 92.

[0072] In a manner similar to that shown in the aforementioned U.S. Pat.No. 6,250,197 incorporated herein by reference, the tubular mountingstud 86 is releasably retained within the socket 84 by inserting thestud 86 downwardly into the socket 84 until the tapered stud portion 90engages a complementarily configured interior tapered surface 100 on thesocket, sequentially placing an annular tapered collet member 102 and alock nut washer 104 on the lower stud end, and then tightening a locknut 106 onto the threaded stud end 88 to draw the tapered collet memberinto engagement with a complementarily configured interior surfaceportion of the socket 84. Before the lock nut 106 is tightened, adownwardly projecting locating pin 108 on the azimuth stop plate 92 isinserted into a peripheral groove 110 on the upper end of the socket 84to rotationally align the inserted stud 86 with the socket 84 in apredetermined manner.

[0073] With reference now to FIGS. 13-15, the pintle block structure 72is elongated in an inboard-outboard direction and has an inboard flangedend portion 112 which is suitably bolted to the horizontally centralportion 46 c of the tow plate 46. Just outboard of the flange 112 aharmonic balancer structure 114 (similar to the harmonic balancerstructure 508 shown in U.S. Pat. No. 6,250,197) is secured to the pintleblock structure 72 and forwardly projects outwardly therefrom. Outboardof the harmonic balancer structure 114 is a hollow body portion of thepintle block structure 72 which has spaced apart top and bottom walls inwhich circularly cross-sectioned openings 116, 118 respectively extend.Openings 116, 118 have oppositely tapered conical interior surfaces, andare spaced apart along an axis parallel to the longitudinal support armaxis 70.

[0074] Positioned between the interior surface portions 116, 118 are adiametrically opposite pair of circularly cross-sectioned sidewalllocking openings 120 extending transversely through the pintle blockstructure body. For purposes later described herein, a spaced pair ofparallel mounting flanges 122, 124 project outwardly from the outboardend of the pintle block structure, with each of the mounting flanges122, 124 having a spaced pair of circular openings 126, 128 formedtherethrough.

[0075] As best illustrated in FIGS. 14 and 15, the pintle arm assembly52 further includes an annular tapered collet 130, an annular spacermember 132, an annular lock washer 134, and a lock nut 136. The supportarm 68 is operatively installed on the pintle block structure 72, androtationally locked in a non-adjustable position therein, by insertinglower support arm member end portion 74 into the pintle support blockmember openings 116, 118 in a manner bringing the pintle arm opening 78into alignment with the pintle block openings 120, and bringing thetapered support arm surface 80 into engagement with the similarlytapered interior surface of the pintle block opening 116. A locking pin138 is then operatively inserted into the aligned openings 78, 120 (theopenings 78 being lined with annular bushings 79) to rotationally lockthe support arm 68 relative to the pintle block. To further stabilizethe support arm portion 74 disposed within the pintle block 72, thecollet 130, the spacer member 132 and the lock Washer 134 aresequentially placed over the lower end of the support arm, and the nut136 is tightened onto the threaded lower support arm end 76 to therebyforce the tapered collet 130 upwardly into engagement with the taperedinterior surface of the lower pintle block opening 118 to therebyrigidly stabilize the lower support arm portion captively retainedwithin the interior of the pintle block 72.

[0076] As can be seen, compared to the pintle arm assembly shown in U.S.Pat. No. 6,250,197, the novel pintle arm assembly 52 just described isof a simpler, more cost effective construction, requiring considerablyfewer parts while at the same time providing a desirably rigidconnection between the support arm 68 and the pintle block structure 72.

[0077] Turning now to FIGS. 6-12, the machine gun 58 is representativelya .50 caliber machine gun of generally conventional construction andhaving an elongated body portion (receiver) 140 from a front end 142 ofwhich a barrel 144 forwardly projects. A spaced pair of aperturedmounting tabs 146 (one of which being visible in FIG. 9) projectdownwardly from the bottom side of the machine gun body 140. A speciallydesigned annular trunnion nut 148 is threaded onto a front portion ofthe gun body 140 and has a circumferentially spaced series of circularmounting openings 150 extending radially therethrough. Openings 150 arenonthreaded and, as illustrated in FIG. 10 are each lined with anannular, nonthreaded, casehardened steel bushing 152.

[0078] Machine gun 58 is removably secured to the underlyingshock-absorbing cradle assembly 56 which is substantially similar inconstruction and operation to the cradle assembly illustrated anddescribed in U.S. Pat. No. 6,250,197 which has been incorporated byreference herein. The receiver 140 is releasably secured to the cradleassembly 56 using a ball lock pin 154 (see FIG. 9) inserted through thereceiver flanges 146 and an associated pair of cradle flanges 156 (oneof which is visible in FIG. 8).

[0079] At the front end of the cradle assembly 56 (see FIG. 8) are aspaced pair of upstanding corner mounting bosses 158 having circularopenings 160 extending horizontally therethrough, and smaller diametercircular locking openings 161 extending vertically through the upperends of the bosses 158 into the interiors of their horizontal openings160. According to a feature of the present invention, the trunnion nut148, and thus a front end portion of the machine gun receiver 140, arereleasably locked to the underlying cradle assembly 56 by placing thetrunnion nut 148 between the bosses 158, in a manner such that adiametrically opposite pair of the nut openings 150 are aligned with theboss openings 160, and utilizing a pair of specially designed lockingstuds 162.

[0080] Each mounting stud 162, as best illustrated in FIG. 8, has atubular body 164 sized to be complementarily and slidably received inone of the boss openings 160, a reduced diameter, nonthreadedcylindrical inner end portion 166 sized to be complementarily andslidably received in one of the trunnion nut openings 150, a transversecircular locking opening 168 extending transversely through an outer endportion of the body 164, and a small peripheral gripping projection 170on the outer end of the body 164 which facilitates the manualinstallation and removal of the stud 162.

[0081] With the trunnion nut 148 positioned between the bosses 158 asshown in FIG. 8, the studs 162 are inserted inwardly through the bossopenings 160 to insert the inner stud end portions 166 in the trunnionnut openings 150 facing the boss openings 160, and to bring the studlocking openings 168 into alignment with the upper boss end openings161. The inserted studs 162 are then releasably retained in thesetrunnion nut-locking orientations by inserting ball lock pins 172downwardly through the aligned stud and boss opening pairs 168, 161.This releasably locks a front end portion of the machine gun receiverportion 140 to the underlying cradle structure 56 without the necessityof any threaded connection between the trunnion nut 148 and theassociated cradle locking structure.

[0082] The yoke assembly 54 (see FIG. 12) is similar to the yokeassembly illustrated and described in U.S. Pat. No. 6,250,197, underliesthe cradle assembly 56, and has upwardly projecting pairs of clevisplates 174 which straddle and are pivotally pinned to correspondingclevis structures 176 on the cradle assembly 56 to thereby permit thecradle assembly 56 (and thus the machine gun 58 supported thereon) toelevationally pivot about a horizontal axis 178 relative to the yokestructure 54.

[0083] With reference now to FIGS. 11 and 12, the yoke assembly has abottom center block structure 180 having a bottom side opening (notvisible) that upwardly and rotatably receives the tubular upper endportion 96 (see FIG. 11) of the mounting stud 86, the upper end portion96 being captively retained in the center block 180 by means of aretaining pin 182 extended through the center block 180 and received ina peripheral portion of the exterior annular groove 98 formed in theupper mounting stud end portion 96.

[0084] This rotational connection between the yoke assembly 54 and thepintle arm assembly 52 permits the machine gun 58 to pivot relative tothe stationary pintle arm assembly 52 about a generally vertical azimuthaxis 184 in addition to being pivotable relative to the stationarypintle arm assembly about the horizontal elevational axis 178. Asillustrated in FIG. 1, the azimuth axis 184 is forwardly inclinedrelative to a vertical reference axis 186 by a small angle A which isrepresentatively equal to the forward rotor axis tilt—i.e.,approximately three degrees.

[0085] In this manner, with the machine gun 58 in its upper limitposition and the helicopter in a level orientation, the elevationalangle of the machine gun's firing axis is automatically increased as themachine gun 58 is rearwardly pivoted about the forwardly inclinedvertical axis 184, and is automatically decreased as the machine gun isforwardly pivoted about the axis 184. This advantageously increases thegun's side and rear firing ranges, while at the same time maintaining asafe vertical clearance distance between the gun's firing axis and thedrooped front end of the helicopter's rotor blade tip envelope when thegun is in its forwardmost azimuth orientation. The total availableazimuth rotation arc of the machine 58 is set by the previouslymentioned stop projections 94 (see FIG. 11) on the azimuth plate 92. Astop projection 188 (see FIG. 4) on the underside of the center blockstructure 180 engages and is stopped by the azimuth plate projections 94at the opposite azimuth rotational limit positions of the machine gun.

[0086] With both the machine gun 58 and its associated ammunitionbox/booster assembly 60, together with the balance of the armamentapparatus 50, disposed externally of the cabin area (see FIG. 1), thegunner's windows 26 can be closed during inclement weather duringperiods when the gun is not being fired, the cabin area is not clutteredwith armament apparatus, and the use of larger machine guns, such as theillustrated 0.50 caliber machine gun 58, is substantially facilitated.The pintle arm assembly 52 has a rugged construction which has onlyminimal vertical and horizontal “play” therein, thereby substantiallyincreasing the firing accuracy of the gun.

[0087] A portion of an alternate embodiment 190 of the previouslydescribed pintle arm assembly 52 is illustrated in FIGS. 16 and 17. Thepintle arm assembly 190 is identical to the pintle arm assembly 52 withthe exceptions that (1) the support arm member 68 has a uniformcross-section along its length and is provided with two sets ofdiametrically opposed openings 192 in a lower end portion thereof, and(2) the pintle support block 72 has spaced pairs of aligned openings 194on opposite sides thereof inboard of the mounting flanges 122, 124. Thesupport arm 68 is operatively installed in the pintle support block 72by inserting a lower end portion of the support arm 68 into the interiorof the pintle support block 72 in a manner aligning the support armopenings 192 with the pintle block openings 194, and then inserting twoexpansion pins 196 through the aligned opening sets 194, 192 torotationally and translationally lock the inserted support arm lower endportion within the interior of the pintle support block 72.

[0088] Turning now to FIGS. 6, 7 and 18-20, the ammunition box/boosterassembly 60 includes a generally rectangular ammunition box 200 (seeFIGS. 18-20) having an outlet opening 202, a booster housing 204 havingan access opening 206 and a discharge opening 207, and a speciallydesigned electric booster motor 208 having external rotatable drivesprockets 210 and 211, the motor 208 being mounted in a subsequentlydescribed unique manner within the booster housing 204 between itsaccess opening 206 and its discharge opening 207.

[0089] The booster housing 204 is removably secured to the ammunitionbox 200 with the booster housing access opening 206 aligned with theammunition box outlet opening 202, and the booster housing dischargeopening 207 facing downwardly. As illustrated in FIGS. 6 and 7, a bottomside portion of the ammunition box 200 is suitably secured to spacedapart mounting structures 212,214 anchored to the top side edge portion46 d of the tow plate 46. This positions the ammunition box/boosterassembly inboard of the pintle support arm 68 and the machine gun 58,with the booster housing 204 facing rearwardly. Ammunition box 200 holdsa length of belted ammunition 216 which is engaged and driven outwardlythrough the booster housing discharge opening 207 by the rotationallydriven sprockets 210 and 211, and routed to the machine gun 58, duringfiring of the gun.

[0090] According to a feature of the present invention, the boostermotor 208 is specially designed to permit it to be rapidly installedwithin or removed from the booster housing 204 without the use of toolsof any sort. As illustrated in FIGS. 19 and 20, the booster motor 208has a cylindrical body 218 on which the sprockets 210,211 are coaxiallyand rotatably carried, and generally annular mounting members 220secured to the opposite ends of the body 218. Aligned, diametricallyopposite grooves 222 are formed in each of the annular mounting members220 as may be best seen in FIG. 20.

[0091] Disposed within the booster housing 204, inwardly adjacentopposite ends of the access opening 206, are a spaced pair of mountingbosses 224 (only one of which is visible), each of the bosses 224 havingan upper end opening 226 formed therein. Bosses 224 underlie a pair ofexterior mounting bosses 228, with the openings 226 in the interiorbosses 224 being aligned with vertical through-holes 230 in the exteriorbosses 228. To rapidly install the booster motor 208 within the boosterhousing 204 without using any tool, the motor 208 is simply insertedinwardly through the booster housing access opening 206 in a mannerplacing the motor end grooves 222 in alignment with the opposing bossopening pairs 226,230. Ball detent locking pins 232 are then downwardlyinserted sequentially through the exterior boss openings 230, the motorend grooves 222 and into the interior openings 226, thereby captivelyretaining the booster motor 208 within the booster housing 204.

[0092] The booster housing 204 is then secured to the ammunition box 200over its outlet opening 202. To subsequently remove the booster motor208, for replacement with another booster motor 208, the booster housing204 is simply removed from the ammunition box 200, the pins 232 arepulled out, the booster motor 208 is removed, and another booster motoris installed within the booster housing 204 as previously described. Thebooster housing 204 is then re-attached to the ammunition box.

[0093] Referring now to FIGS. 1, 4 and 5, as previously mentioned theflare dispenser 62 is mounted on the specially configured rear endportion 46 b of the tow plate 46. This places the installed flaredispenser 62 generally beneath the pivotal mounting location of themachine gun 58 and accordingly eliminates any potential interferencebetween the gun barrel 144 and the flare dispenser 62 as the gun isbeing swung through its azimuth arc in a depressed orientation.

[0094] Turning now to FIGS. 2, 3, 6 and 21-23, the missile launcherassembly 64, which is positioned outboard of the pintle support assembly52, is of a generally conventional construction and may be generallyreferred to as an external stores apparatus. As used herein, the term“external stores” encompasses armament apparatus, such as missiles,rockets and rocket launchers, additional guns, electronics, etc. whichare carried externally to the aircraft and are typically, though notnecessarily, jettisonable (via, for example, a bomb rack or the like).

[0095] Representatively, the missile launcher assembly 64 includes amissile support frame 234 (see FIG. 2) that carries two forwardlydirected missiles 236 which underlie the support frame 234. An upperside portion of the support frame 234 is connected to hook portions 238(see FIG. 23) on the underside of a conventional bomb rack 240 overlyingthe support frame 234. The bomb rack 240 is carried within a housing 242which, together with the bomb rack 240, forms a portion of a speciallydesigned external stores support structure 244 (see FIG. 21) that, in asubsequently described manner, supports the missile launcher assembly 64(or other external stores apparatus as the case may be) on the pintlesupport block 72, and thus on the tow plate 46.

[0096] As best illustrated in FIGS. 21-23, the external stores supportstructure 244 includes a perforated outboard face plate 246, an inboardbase plate 248 secured to the face plate 246 by a support tube 250sloped downwardly in an inboard direction, and a mounting lug 252projecting outwardly from a lower inboard side portion of the base plate248.

[0097] With reference now to FIG. 22, the face plate 246 is elongated ina front-to-rear direction and has outwardly projecting front and rearadjustment ears 254,256 on opposite ends thereof, an internally threadedtubular pivot support post 258 projecting outwardly from an uppercentral portion of the outboard side of the face plate 246, and arcuatefront and rear adjustment slots 260,262 extending through the plate 246on lower front and rear portions thereof. Mounting lug 252 (see FIG. 6also) has spaced apart mounting openings 264 extending therethrough.

[0098] The housing structure 242 is secured to the balance of theexternal stores support structure 244 in the following manner. A sockethead bolt 266 is sequentially passed through a flat washer 268, aspindle washer 270 and a bushed circular opening 272 extending throughthe housing structure 242, and is threaded into the pivot support post258. Additionally, bolts 274 are sequentially passed through washers276, housing holes 278, the bomb rack 240, annular sway brace spacers280, and the arcuate face plate slots 260 and 262, with flat washers 282and nuts 284 being secured to the inner ends of the bolts 274 on theinboard side of the face plate 246.

[0099] Front and rear elevation bolts 286,288 are extended through locknuts 289 and washers 291 and threaded downwardly through threadedopenings 290 in the face plate adjustment ears 254 and 256, with thelower ends of the bolts 286,288 overlying and engaging outwardlyprojecting lugs 292 on front and rear inboard side portions of thehousing 242 (see FIG. 23). The external stores support structure 244 isremovably anchored to the pintle support block 72, as schematicallyshown in phantom in FIG. 6, by placing the base plate lug 252 betweenthe pintle block flanges 122, 124 in a manner aligning the lug holes 264with the flange holes 126, 128 and then extending schematically depictedexpansion pins 294 through the aligned holes in the lug 292 and flanges122, 124.

[0100] The mounting of the bomb rack housing 242 to the supportstructure face plate 246 in the manner described above permits thehousing 242, and thus the supported missiles 236 (or other externalstores apparatus as the case may be) to be elevationally adjusted abouta horizontal inboard-outboard axis 296 (as indicated by the double-endedarrow 298 in FIG. 21) extending longitudinally through the pivot supportpost 258. Such elevational adjustment is effected by (1) loosening thenuts 284 (see FIG. 22) to permit the bolts 274 to move through thearcuate face plate slots 260 and 262, (2) loosening the lock nuts 284and upwardly retracting one of the elevation bolts 286,288 anddownwardly advancing the other elevation bolt to pivotally adjust thebomb rack frame 246 about the elevation axis 196, and then (3)retightening the nuts 284,294 to lock the missiles 236 in theirelevationally adjusted positions. A similar adjustment structure couldbe provided to permit the housing 242 to be selectively adjusted about avertical axis as well.

[0101] Turning now to FIG. 24, in addition to the previously describedcomponents thereof the external armament apparatus 50 (in the absence ofthe refueling boom 49) may also include the conventional forward-lookinginfrared sensor (FLIR) 66 which is supported on the front edge portion46 a of the tow plate 46 by a specially designed mounting structure 300positioning the sensor 66 forwardly of the tow plate 46. The mountingstructure 300 includes a first mounting block 302 bolted to the frontedge portion 46 a of the tow plate 46, a support tube 304 longitudinallyprojecting forwardly from the mounting block 302, and a second mountingblock 306 secured to the forward end of the support tube 304. Ahorizontally disposed flange 308 is secured to the front side of themounting block 308 by vertical webs 310 and is bolted to a top endportion 312 of the sensor 66. As opposed to its normal mounting positionon a front underside portion of the helicopter 10, this unique sponsonmounting of the sensor 66 provides several advantages including enhancedfront end ground clearance and improved aircraft weight andbalance/center of gravity.

[0102] Referring now to FIG. 12, a spaced pair of parallel, facingelevation limiting plates 314 (only one of which is visible in FIG. 12)project downwardly from front bottom side portions of the cradleassembly 56. Each plate 314 has an arcuate bottom edge 316 in whichupper and lower notches 318,320 are formed. With the missile launcherassembly 64 (see FIG. 2) removed, and the previously described gunmounting stud 86 (see FIGS. 11 and 13) installed, the cradle assembly 56(and thus the machine gun 58) may be pivoted forwardly and downwardlythrough an elevation arc of approximately 50 degrees before the upperplate notches 318 engage the yoke assembly center block 180 and preventfurther downward pivoting of the machine gun 58. Upward pivoting of themachine gun 58 is limited to a generally horizontal position by thedownward receipt of outer ends of a latch bar member 322 in slots 324 inlatch members 326 on the underlying yoke assembly 54 as illustrated anddescribed in U.S. Pat. No. 6,250,197.

[0103] As previously described, the stop projections 94 on the azimuthstop plate portion of the mounting stud 86 limit the azimuth rotation ofthe yoke assembly 54, and thus the machine gun 58, to a predeterminedarc. As diagrammatically depicted in FIGS. 25 and 26, with the missilelauncher assembly 64 removed and the mounting stud 86 installed, theazimuth arc 328 is representatively about 171 degrees from the forwardlimit of the gun 58 to the rearward limit of the gun 58, with a fulldepression arc 330 of about 50 degrees being available throughout thefull azimuth arc 328.

[0104] According to a feature of the present invention, with the missilelauncher assembly 64 installed a specially designed elevation limitingsystem, subsequently described herein, is provided and functions in aunique manner to automatically alter the available gun depression arc,in response to azimuth rotation of the gun, to prevent potentialinterference between the gun's bullet path and a front end portion ofthe installed missile launcher assembly 64. As diagrammatically shown inFIGS. 27 and 28, with this elevation limiting system installed, a totalavailable gun travel azimuth arc 328 of approximately 164 degrees isprovided as shown in FIG. 27. However, the full available 50 degreedepression arc 330 (see FIGS. 27 and 28) is permitted only in a rearportion 328 a of the azimuth arc 328. In an approximately 64 degreefront portion 328 b of the available azimuth arc 328, only a limiteddepression arc 330 a of approximately 18 degrees (see FIG. 28) ispermitted by the elevation limiting system, generally denoted by thereference numeral 332, which will now be described in conjunction withFIGS. 29-32.

[0105] In FIG. 29 the cradle assembly 56 has been forwardly rotated tobe within the front portion 328 b of the available azimuth arc 328 shownin FIG. 27, is downwardly pivoted to its depression limit positionwithin such azimuth range of approximately 18 degrees, and is beingprecluded by the elevation limiting system 332 from being furtherpivoted in a downward direction.

[0106] Turning now to FIG. 30, the elevation limiting system 332includes a modified azimuth stop plate 92 a incorporated in the mountingstud 86, the previously mentioned elevation limiting plates 314, a bossmember 334 anchored to the yoke assembly center block 180 and overlyinga top side peripheral portion of the azimuth stop plate 92 a, avertically movable cam follower member 336, and a vertically disposedcoiled tension spring 338.

[0107] The stationary azimuth plate 92 a has, on a peripheral top sideportion thereof, an arcuate track 340 with a lower arcuate portion 340 acorresponding to the rear azimuth arc portion 328 a (see FIG. 27), andan upwardly ramped area 340 b connecting the lower arcuate track portion340 a with an elevated arcuate track portion 340 c corresponding to theforward azimuth arc portion 328 b (see FIG. 27).

[0108] Follower member 336, as shown in FIG. 30, has an upwardlyprojecting stop portion 344 joined to a horizontally offset cylindricalguide portion 346 by a tapered intermediate portion 348. The cylindricalguide portion 346 is slidingly received in a circular bore 350 extendingvertically through the boss 334. The lower end of the guide portion 346has a cam roller 352 secured thereto (see FIG. 32) which is rollablealong the track 340 as the yoke assembly 54 is rotated relative to thestationary azimuth plate 92 a. The lower end of the spring 338 isanchored, as at 354, to the center block 180, and the upper end of thespring 338 is anchored, as at 356, to the follower member stop portion344 for vertical movement therewith relative to the center block 180.Spring 338 resiliently biases the follower member 336 downwardly towardthe stationary azimuth stop plate 92 a.

[0109] With the cradle assembly in its FIG. 29 orientation, the followerwheel 352 (see FIG. 32) is on the upper portion 340 c of the azimuthplate track 340, and the follower member stop portion 344 is in a raisedposition in which acts as an abutment for the lower limiting platenotches 320, thereby blocking further downward pivoting of the cradleassembly 56 (and thus the gun 58) past an 18 degree depression anglewhen the gun 58 is in the 0-64 degree azimuth arc 328 b shown in FIG.27.

[0110] In FIGS. 31 and 32, the cradle assembly 56 is horizontallypivoted rearwardly to within the 64-164 degree azimuth portion 328 ashown in FIG. 27, and is downwardly pivoted to its full depression angleof approximately 50 degrees. In this cradle/gun orientation, thefollower wheel 352 is engaged with the lower track portion 34 a (seeFIG. 32), thereby lowering the follower member stop portion 318 relativeto its FIG. 30 position. In turn, this lowered position of the stopportion 318 permits the cradle assembly 56 (and thus the gun 58) to belowered past its FIG. 29 depression angle to its fully depressed (50degree down) orientation at which point the upper plate notches 318engage the follower member stop portion 344 to prevent further downwardpivoting of the gun 58 while it is in its 64-164 degree azimuth arcportion 328 a shown in FIG. 27.

[0111] In the event that the gun 58 is pivoted forwardly from theazimuth arc portion 328 a shown in FIG. 27 while in a depression anglegreater than 18 degrees, the forcible engagement of the follower wheel352 with the track ramp 340 b prevents the gun from being forwardlyswung into the forward azimuth arc portion 238 b shown in FIG. 27 unlessthe gun 58 is raised to an elevation angle of less than 18 degrees. Itcan thus be seen that the elevation limiting system functions toautomatically alter the available gun depression angle in response toazimuth rotation of the gun 58. Representatively, this automaticalteration of the available gun depression angle provides two differentdepression angle ranges corresponding to two different azimuth rotationarc portions. However, it should be readily appreciated that more thantwo different depression angle ranges could be built into the elevationlimiting system 332 if desired.

[0112] As will be readily be appreciated by those of skill in thisparticular art, a variety of modifications could be made to therepresentatively illustrated external armament apparatus 50 withoutdeparting from principles of the present invention. For example, but notby way of limitation, machine guns of types other than therepresentatively illustrated 0.50 caliber machine gun 58 (for example7.62 mm mini-guns or 7.62 mm single barrel machine guns) could beutilized, the armament apparatus could be mounted on aircraft (such asfixed wing aircraft) other than helicopters, and various ones of thepreviously described components could be selectively left out of theoverall armament combination described above. As examples, the missilelauncher could at least be temporarily omitted from the overall armamentpackage, the machine gun and ammo box combination could be the totalweaponry compliment, the FLIR sensor could be omitted, or other armamentcomponent combinations could be utilized.

[0113] The foregoing detailed description is to be clearly understood asbeing given by way of illustration and example only, the spirit andscope of the present invention being limited solely by the appendedclaims.

What is claimed is:
 1. Armament apparatus for an aircraft, comprising: alanding gear structure; a mounting member secured to said landing gearstructure and having an opening extending therethrough along a firstaxis; an elongated support arm extending along a vertically inclinedsecond axis and having a lower end coaxially received in said mountingmember opening, and an upper end; machine gun support structure securedto said upper end of said support arm; and attachment structurenonrotatably locking said lower end of said support arm to said mountingmember.
 2. The armament apparatus of claim 1 wherein: said landing gearstructure is a sponson structure having a tow plate, and said mountingmember is secured to said tow plate.
 3. The armament apparatus of claim1 further comprising: an external stores support structure projectingoutwardly from said landing gear structure in an outboard direction andhaving an outboard end portion on which external stores apparatus may bemounted.
 4. The armament apparatus of claim 3 wherein: said mountingmember has an end portion disposed outboard of said lower end of saidelongated support member, and said external stores support structure issecured to said end portion of said mounting member.
 5. The armamentapparatus of claim 3 further comprising: external stores apparatussecured to said outboard end portion of said external stores supportstructure.
 6. The armament apparatus of claim 5 wherein: said externalstores apparatus is a missile launcher assembly.
 7. The armamentapparatus of claim 3 wherein: said outboard end portion of said externalstores support structure is pivotally adjustable relative to the balanceof said external stores support structure about at least one axis. 8.The armament apparatus of claim 7 wherein: said outboard end portion ofsaid external stores support structure is pivotally adjustable relativeto the balance of said external stores support structure about ahorizontal axis.
 9. The armament apparatus of claim 3 wherein: one ofsaid external stores support structure and said mounting member has alug projection thereon, and the other of said external stores supportstructure and said mounting member has a spaced pair of flanges thereon,said lug projection being captively retained between said flanges. 10.The armament apparatus of claim 3 wherein: said outboard end portion ofsaid external stores support structure includes a housing structure anda bomb rack carried by said housing structure for pivotal movementtherewith relative to the balance of said external stores supportstructure, and said armament apparatus further includes threadedadjustment members operative to pivotally adjust said housing and saidbomb rack relative to the balance of said external stores supportstructure.
 11. The armament apparatus of claim 1 further comprising: amachine gun carried by said machine gun support structure and beingrotatable about a generally vertical third axis and angled relative tosaid second axis, and about a fourth axis transverse to said third axis.12. The armament apparatus of claim 11 wherein: said machine gun is a.50 caliber machine gun.
 13. The armament apparatus of claim 1 wherein:said aircraft is a helicopter.
 14. The armament apparatus of claim 1wherein: said attachment structure includes a pin structure extendingthrough said mounting member and said lower end of said support armtransversely to said first axis.
 15. Armament apparatus for an aircraft,comprising: a landing gear structure; a mounting member secured to saidsponson structure, said mounting member having an opening extendingtherethrough along a first axis, said opening having axially spacedapart conically tapered first and second annular interior surfaceportions; an elongated support arm extending along a second axis andhaving a first end portion coaxially received in said support memberopening, and a second end portion spaced apart from said first endportion along said second axis, said first end portion having aconically tapered annular exterior surface portion complementarilyengaging said first interior surface portion of said mounting memberopening; a machine gun support member secured to said second end of saidsupport arm and extending along a third axis angled relative to said issecond axis; and attachment structure locking and stabilizing said firstend portion of said support arm within said opening in said mountingmember.
 16. The armament apparatus of claim 15 wherein: said landinggear structure is a sponson structure having a tow plate, and saidmounting member is secured to said tow plate.
 17. The armament apparatusof claim 15 wherein: said aircraft is a helicopter.
 18. The armamentapparatus of claim 15 wherein: said attachment structure includes atapered annular collet member circumscribing said first end portion ofsaid support arm and being held in forcible, complementary engagementwith said second interior surface portion of said mounting member by anut threaded onto said first end portion of said elongated support arm.19. The armament apparatus of claim 18 wherein: said attachmentstructure further includes a pin structure transversely extendingthrough said mounting member and said first end portion of saidelongated support arm.
 20. The armament apparatus of claim 15 wherein:said attachment structure includes a pin structure transverselyextending through said mounting member and said first end portion ofsaid elongated support arm.
 21. Armament apparatus for an aircraft,comprising: a landing gear structure having front, rear and outboardside portions; an elongated machine gun support arm member having alower end secured to said landing gear structure, said machine gunsupport arm member longitudinally extending along a rearwardly andupwardly inclined axis; and an external stores support structure securedto said landing gear structure and projecting therefrom in an upwardlysloped outboard direction, said external stores support structure havingan outboard end portion with a latching section operative to releasablyengage and support external stores apparatus.
 22. The armament apparatusof claim 21 wherein: said armament apparatus further comprises amounting member secured to said landing gear structure, and sad lowerend of said support arm member and an inboard portion of sad externalstores support structure are secured to said mounting member.
 23. Thearmament apparatus of claim 21 wherein: said outer end portion of saidexternal stores support structure is pivotally adjustable about at leastone axis relative to the balance of said external stores supportstructure.
 24. The armament apparatus of claim 21 wherein: said aircraftis a helicopter.
 25. The armament apparatus of claim 21 wherein: saidlanding gear structure is a sponson tow plate.
 26. Armament apparatusfor an aircraft, comprising: a landing gear structure; an elongatedsupport arm having a lower end anchored to said landing gear structure,and an upper end positioned at a higher level that said lower end;machine gun support structure mounted on said upper end of said supportarm for azimuth rotation relative thereto about a generally verticalaxis, and elevation rotation about a generally horizontal axis; andelevation limiting structure associated with said machine gun supportstructure and operative to variably limit the available elevationrotation of said machine gun support structure in response to azimuthrotation thereof.
 27. The armament apparatus of claim 26 wherein: saidlanding gear structure includes a tow plate, and said lower end of saidsupport arm is anchored to said tow plate.
 28. The armament apparatus ofclaim 27 wherein: said aircraft is a helicopter.
 29. The armamentapparatus of claim 26 wherein: said machine gun support structure ispivotable through an azimuth arc having first and second portions, andsaid elevation limiting structure is operative to provide differentavailable elevational arcs for said machine gun support structure ineach of said first and second azimuth arc portions.
 30. The armamentapparatus of claim 29 wherein: said elevation limiting structure isoperative, in response to azimuth rotation of said machine gun supportstructure to provide a different downward rotation limit for saidmachine gun support structure in each of said first and second azimutharc portions.
 31. The armament apparatus of claim 30 wherein: saidmachine gun support structure is a cradle assembly, said armamentapparatus further includes a yoke assembly underlying said cradleassembly, said cradle assembly being secured to said yoke assembly andpivotable relative thereto about said generally horizontal axis, avertical post structure secured to said upper end of said support armand having a horizontal azimuth stop plate portion, said yoke assemblybeing secured to said post structure and being pivotable relativethereto about said generally vertical axis, and said elevation limitingstructure includes an elevation limiting member carried by said yokeassembly for vertical movement relative thereto, in response to rotationof said yoke assembly about said generally vertical axis, between firstand second positions in which said elevation limiting member variablyblocks downward pivotal movement of said yoke assembly.
 32. The armamentapparatus of claim 31 wherein: said azimuth stop plate portion has anupper side with a ramped cam track disposed thereon, said elevationlimiting member has a lower rolling portion engaging said track, andsaid elevation limiting structure further includes a spring memberresiliently biasing said elevation limiting member downwardly towardsaid upper side of said azimuth stop plate portion.
 33. Machine gunmounting apparatus comprising: a support member having spaced apartfirst and second portions; a machine gun support structure secured tosaid first portion for azimuth and elevational rotation relative theretorespectively about mutually perpendicular first and second axes; andelevation limiting structure operative to variably limit the availableelevational rotation of said machine gun support structure, in differentazimuth arc portions, in response to azimuth rotation thereof.
 34. Themachine gun mounting apparatus of claim 33 wherein: said elevationlimiting structure includes an elevation limiting member carried by saidsupport structure for variable movement relative to the balance thereof,parallel to said first axis, in response to azimuth rotation of saidsupport structure about said first axis.
 35. The machine gun mountingapparatus of claim 34 wherein: said support structure includes a machinegun support cradle elevationally pivotable about said second axis, andsaid elevation limiting member is operative to variably block downwardelevation movement of said cradle structure in response to rotation ofsaid support structure about said first axis.
 36. Machine gun mountingapparatus comprising: a support structure having opposing mountingblocks with facing openings therein; a machine gun trunnion nutsecurable to a machine gun at the juncture of its receiver and barrelportions and having a diametrically opposed pair of nonthreaded radiallyextending openings therein, said trunnion nut being positionable betweensaid mounting blocks with said openings in said trunnion nut beingaligned with said openings of said mounting block; a pair ofnon-threaded trunnion studs each positionable in a locking orientationwithin one of the mounting block openings and an adjacent trunnion nutopening; and a retaining structure for releasably retaining saidtrunnion studs in said locking orientations thereof.
 37. The machine gunmounting apparatus of claim 36 wherein: said retaining structureincludes first pin openings extending transversely through said studs,second pin openings extending through said mounting blocks and beingalignable with said first pin openings when said studs are operativelyreceived in said mounting block and trunnion nut openings, and retainingpins removably insertable in the aligned mounting block and studopenings.
 38. The machine gun mounting apparatus of claim 36 wherein:each of said studs has a non-threaded cylindrical body complementarilyreceivable in one of said mounting block openings, and a reduceddiameter cylindrical inner end portion complementarily receivable in oneof said trunnion nut openings.
 39. The machine gun mounting apparatus ofclaim 36 wherein: each of said trunnion nut openings is lined with anannular, casehardened steel bushing.
 40. The machine gun mountingapparatus of claim 36 wherein: said support structure is a cradlestructure having shock absorbers operably incorporated therein. 41.Armament apparatus for an aircraft, comprising: a landing gearstructure; a machine gun support arm member secured to said landing gearstructure and projecting in an outboard direction therefrom, saidmounting member having a machine gun support arm end-receiving openingextending therethrough along a rearwardly and upwardly inclined axis,and at least one arm locking opening extending therethrough along asecond axis transverse to said first axis; and external stores apparatussecured to said machine gun mounting member outboard of said support armend-receiving opening.
 42. The armament apparatus of claim 41 wherein:said external stores apparatus is a missile launcher assembly.
 43. Thearmament apparatus of claim 41 wherein: said aircraft is a helicoptersaid landing gear structure includes a sponson tow plate, and saidmachine gun mounting member is secured to said sponson tow plate. 44.The armament apparatus of claim 41 wherein: said support armend-receiving opening has first and second oppositely and conicallytapered interior surface portions spaced apart along said first axis.45. Armament apparatus for an aircraft, comprising: a landing gearsponson structure having a tow plate with front portion, a rear portion,and a central portion disposed between said front and rear portions; amachine gun mounting member secured to said central tow plate portion;and a flare dispenser secured to said rear portion of said tow plate.46. The armament apparatus of claim 45 wherein: said aircraft is ahelicopter.
 47. The armament apparatus of claim 45 wherein: said machinegun mounting member has a machine gun support arm end-receiving openingextending therethrough along a rearwardly and upwardly inclined firstaxis.
 48. The armament apparatus of claim 47 wherein: said machine gunmounting member has at least one locking opening extending therethroughalong a second axis transverse to said first axis.
 49. The armamentapparatus of claim 45 further comprising: a forward-looking infraredsensor secured to said front portion of said tow plate.
 50. Armamentapparatus for an aircraft, comprising: a landing gear sponson structurehaving a tow plate with a front portion, a rear portion, and a centralportion disposed between said front and rear portions; and aforward-looking infrared sensor secured to said front portion of saidlanding gear sponson structure.
 51. The armament apparatus of claim 50wherein: the infrared sensor is disposed forwardly of said front end ofsaid tow plate.
 52. The armament apparatus of claim 50 wherein: saidinfrared sensor has an upper end portion, and said infrared sensor issecured to said front tow plate portion by a mounting structure having afirst mounting portion anchored to said front tow plate portion, anelongated support member longitudinally extending forwardly from saidfirst mounting portion and having a forward end, and a second mountingportion secured to said forward end and to said upper end of saidinfrared sensor.
 53. Armament apparatus for an aircraft, comprising: alanding gear sponson structure having a tow plate with a front portion,a rear portion, a central portion disposed between said front and rearportions, and an outboard side; a hollow support block structure securedto said central portion and projecting outwardly from said outboardside; a rearwardly and upwardly inclined elongated support arm memberhaving a lower end secured within said support block structure, and anupper end; a machine gun rotatably mounted on said upper end of saidsupport arm member; external stores apparatus secured to said hollowsupport block structure outboard of said support arm member; a flaredispenser secured to said rear portion of said tow plate; and a beltedammunition box secured to said tow plate above said hollow support blockstructure and disposed inboard of said support arm member.
 54. Thearmament apparatus of claim 53 wherein: said external stores apparatusis a missile launcher assembly.
 55. The armament apparatus of claim 53wherein: said aircraft is a helicopter.
 56. The armament apparatus ofclaim 53 further comprising: a forward-looking infrared sensor securedto said front portion of said tow plate.
 57. The armament apparatus ofclaim 53 wherein: said machine gun is a 0.50 caliber machine gun.\ 58.The armament apparatus of claim 53 wherein: said machine gun isrotatable about a generally vertical but upwardly and forwardly inclinedaxis.
 59. the armament apparatus of claim 58 wherein: said axis isforwardly inclined at an angle of approximately three degrees.
 60. Thearmament apparatus of claim 53 wherein: said missile launcher isdisposed outboard of said support block structure.
 61. The armamentapparatus of claim 53 wherein: said missile launcher is pivotallyadjustable relative to said support block structure about at least oneaxis.
 62. Belted ammunition storage and feed apparatus for a machinegun, comprising: a belted ammunition storage box having an outletopening; a booster housing removably secured to said storage box oversaid outlet opening and having an ammunition discharge opening, and anaccess opening; and a sprocketed electric drive motor structure operableto drive belted ammunition from the interior of said ammunition storagebox sequentially through said outlet opening and said ammunitiondischarge opening, said drive motor structure being releasably latchedwithin said booster housing and being removable therefrom andinstallable therein, via said access opening, without the use of a tool.63. The belted ammunition storage and feed apparatus of claim 62wherein: said drive motor structure has opposite mounting end portionswith openings extending therethrough, said booster housing has first andsecond sets of spaced mounting portions with mounting openings therein,each said mounting end portion is disposed between the booster housingmounting portions in one of said first and second sets thereof, and saidbelted ammunition and feed apparatus further comprises first and secondpin structures extending through said openings in said drive motor endportion openings and said booster housing mounting portion openings andcaptively retaining said drive motor within said booster housing, saidfirst and second pin structures being removable from said boosterhousing to thereby release said drive motor structure and permit it tobe moved outwardly through said access opening.
 64. The beltedammunition storage and feed apparatus of claim 63 wherein: said accessopening faces said outlet opening.
 65. The belted ammunition storage andfeed apparatus of claim 63 wherein: said mounting end portions aregenerally disc-shaped, and said mounting openings in said mounting endportions extend diametrically therethrough.
 66. The belted ammunitionstorage and feed apparatus of claim 65 wherein: said mounting endportion openings laterally open outwardly through outer side portions ofsaid mounting end portions.
 67. Armament apparatus for an aircraft,comprising: a landing gear sponson structure; a machine gun supported onsaid sponson structure; a belted ammunition storage box having an outletopening and being supported on said sponson structure; a booster housingsecured to said storage box over said outlet opening and having anammunition discharge opening, and an access opening; and a sprocketedelectric drive motor structure operable to drive belted ammunition fromthe interior of said ammunition storage box sequentially through saidoutlet opening and said ammunition discharge opening, said drive motorstructure being releasably latched within said booster housing and beingremovable therefrom and installable therein, via said access opening,without the use of tools.
 68. The armament apparatus of claim 67wherein: said drive motor has opposite mounting end portions withopenings extending therethrough, said booster housing has first andsecond sets of spaced mounting portions with mounting openings therein,each said mounting end portion is disposed between the booster housingmounting portions in one of said first and second sets thereof, and saidbelted ammunition and feed apparatus further comprises first and secondpin structures extending through said openings in said drive motor endportion openings and said booster housing mounting portion openings andcaptively retaining said drive motor structure within said boosterhousing, said first and second pin structures being removable from saidbooster housing to thereby release said drive motor and permit it to bemoved outwardly through said access opening.
 69. The armament apparatusof claim 68 wherein: said access opening faces said outlet opening. 70.The armament apparatus of claim 68 wherein: said mounting end portionsare generally disc-shaped, and said mounting openings in said mountingend portions extend diametrically therethrough.
 71. The armamentapparatus of claim 70 wherein: said mounting end portion openingslaterally open outwardly through outer side portions of said mountingend portions.
 72. A method of controlling the available movement of amachine gun, said method comprising the steps of: supporting the machinegun for rotation about mutually perpendicular first and second axes, andvariably limiting the range of rotation of the supported machine gunabout said first axis in response to rotation of the supported machinegun about said second axis.
 73. The method of claim 72 wherein: saidvariably limiting step is performed in a manner providing for themachine gun separate available pivotal ranges about said first axis whensaid machine gun is respectively within first and second pivotal rangesabout said second axis.
 74. The method of claim 73 wherein: saidsupporting step is performed in a manner such that said first axis isgenerally horizontal and said second axis is generally vertical.
 75. Themethod of claim 73 wherein: said variably limiting step is performedusing a blocking structure, movable in opposite directions parallel tosaid first axis in response to rotation of said machine gun about saidfirst axis, to variably block rotational movement of said machine gunabout said first axis.
 76. A method of constructing ammunition storageand feed apparatus for a machine gun, said method comprising the stepsof: providing a belted ammunition storage box having an ammunition beltoutlet opening; providing a booster housing having an ammunitiondischarge opening and an access opening; installing, without the use ofa tool, a sprocketed electric drive motor structure in said boosterhousing in a manner permitting the installed drive motor structure to besubsequently removed from said booster housing, through said accessopening, without the use of a tool, the installed drive motor structurebeing useable, when said booster housing is operatively installed onsaid storage box over said outlet opening thereof, to drive beltedammunition from the interior of said storage box sequentially throughsaid outlet opening and said ammunition discharge opening; andoperatively securing said booster housing to said storage box over saidoutlet opening.
 77. The method of claim 76 wherein said installing stepincludes the steps of: providing said booster housing with a pair offacing wall openings, forming a connection opening in said electricdrive motor structure, placing said drive motor structure in saidbooster housing with said connection opening disposed between said wallopenings, and releasably inserting a retaining pin into said wallopenings and said connection opening.
 78. The method of claim 77wherein: said releasably inserting step is performed using a ball detentpin.
 79. the method of claim 77 wherein: said electric drive motorstructure has a generally annular outer end portion having diametricallyopposite outer side slots that together define said connection opening,and said releasably inserting step includes the step of releasablyextending said retaining pin through said slots.
 80. A method ofmounting a machine gun on a support structure having a spaced apart pairof facing mounting members with aligned openings therein, said methodcomprising the steps of: mounting a trunnion nut member on the machinegun, said trunnion nut having a diametrically opposed pair ofnonthreaded openings extending radially therethrough, positioning saidtrunnion nut member between said mounting members with said trunnion nutopenings aligned with said mounting member openings; providing a pair ofnonthreaded locking members; positioning first portions of said lockingmembers in said mounting member openings, and second portions of saidlocking members in said trunnion nut openings; and releasably lockingsaid first locking member portions within said mounting member openings.81. The method of claim 80 wherein: said releasably locking step isperformed by extending locking members through aligned openings in saidmounting members and said first locking member portions.
 82. the methodof claim 80 wherein: said method further comprises the step ofconfiguring each of said locking members to have a cylindricalnon-threaded body portion sized to be complementarily received in one ofsaid mounting member openings, and a reduced diameter non-threaded innerend portion sized to be complementarily received in one of said trunnionnut member openings.
 83. A method of arming an aircraft having a landinggear structure, said method comprising: securing a mounting member tosaid landing gear structure, said mounting member having an openingextending therethrough along an upwardly and rearwardly inclined axis;providing an elongated support arm member having first and second endportions spaced apart along an axis; coaxially anchoring said first endportion of said support arm within said mounting member opening;supporting a machine gun on said second end portion of said support armfor azimuth and elevational rotation relative thereto respectively aboutgenerally vertical and horizontal axes; and supporting external storesapparatus on said mounting member outboard of said support arm member.84. The method of claim 83 wherein: said step of supporting externalstores apparatus is performed in a manner permitting pivotal adjustmentof said external stores apparatus about at least one axis.
 85. Themethod of claim 83 wherein: said aircraft is a helicopter.
 86. Themethod of claim 83 wherein: said landing gear structure includes a towplate, and said securing step is performed by securing said mountingmember to said tow plate.
 87. The method of claim 83 wherein: saidcoaxially anchoring step includes the step of extending at least oneretaining pin member through said mounting member and said first endportion of said elongated support arm member along an axis transverse tothe axes of said mounting member opening and said support arm member.88. The method of claim 83 wherein: said first end portion of saidsupport arm member has a conically tapered annular exterior side surfacearea, said mounting member opening has a conically tapered annularinterior surface area, and said coaxially anchoring step includes thestep of forcibly holding said conically tapered annular surface areas ofsaid first support arm member end portion and said mounting memberopening in a complementary engagement with one another.
 89. A method ofarming an aircraft having a landing gear structure with a front portion,said method comprising the steps of: providing a forward-lookinginfrared sensor; and mounting said forward-looking infrared sensor onsaid front portion of said landing gear structure.
 90. The method ofclaim 89 wherein: said aircraft is a helicopter.
 91. The method of claim89 wherein: said landing gear structure includes a sponson tow platehaving a front edge portion, and said mounting step is performed bymounting said sensor on said front edge portion.
 92. The method of claim91 wherein: said mounting step is performed in a manner positioning saidsensor in a forwardly spaced relationship with said front edge portionof said tow plate.
 93. A method of arming an aircraft having a landinggear structure with a front portion, a rear portion, and a centralportion disposed between said front and rear portions, said methodcomprising the steps of: securing a machine gun mounting member to saidcentral portion of said landing gear structure; providing an elongatedsupport arm member; attaching a first end portion of said support armmember to said mounting member in a manner such that a second endportion of said support arm member is rearwardly and upwardly offsetfrom said mounting member; mounting a machine gun on said second endportion of said support arm member for rotation about a pivot area; andsecuring a flare dispenser to said rear portion of said landing gearstructure in a manner positioning said flare dispenser generally beneathsaid pivot area of said machine gun.
 94. The method of claim 93 wherein:said mounting step is performed using a 0.50 caliber machine gun. 95.The method of claim 93 wherein: said aircraft is a helicopter.
 96. Themethod of claim 93 wherein: said landing gear structure is a sponson towplate.
 97. A method of arming an aircraft having a landing gear sponsonstructure having a tow plate with a front portion, a rear portion, acentral portion disposed between said front and rear portions, and anoutboard side, said method comprising the steps of: securing a hollowsupport block structure to said central portion of said tow plate withsaid support block structure projecting outwardly in an outboarddirection therefrom; anchoring a lower end portion of an elongated,substantially straight support arm member within said support blockstructure in a manner such that a second end portion of said support armmember is rearwardly and upwardly offset from said support blockstructure; mounting a machine gun on said second end portion of saidsupport arm member for rotation about a pivot area; securing externalstores apparatus to said support block structure in a manner positioningsaid missile launcher structure outboard of said support blockstructure; securing a flare dispenser to said rear portion of said towplate generally beneath said pivot area of said machine gun; andsecuring a belted ammunition box to a top side edge portion of said towplate above said support block structure and inboard of said support armmember.
 98. The method of claim 97 further comprising the step of:securing a forward-looking infrared sensor to said front portion of saidtow plate.